8 Responses. > 1  the Moon takes an elliptical path around the Earth. The planets make nearly elliptical orbits around the Sun, close enough for reasonable approximations, but the Moonâs Orbit around the Earth is sufficiently influenced by the Sun that it follows a path detectably different from an ellipse.
Quick Answer. In 1896, French scientist Antoine Henri Becquerel discovered radioactivity which was an early contribution to atomic theory. He discovered this phenomenon while experimenting with uranium and a photographic plate. Continue Reading.
He improved Democritusâ first theory. He discovered that atoms of different elements are different from others, and that atoms of the same element are the same size. He also discovered that atoms combine in specific proportions and that all substances are made of atoms. To find this out, he worked with gases.